There are six people in a family namely M, N, O, P, Q and R.

R and O are brother and sister.

N is the brother of Q husband.

P is the father of M and grandfather of R.

Can you calculate the number of male members in the family?

First of all, let us collect all the information we have and form facts based on that.

P is the father of M and the grandfather of R.

O and F are siblings and children of M.

N is the brother of Q husband.

Now we know that there can only be one mother and O and R are children, P is the father and N is he brother. It implies that M and Q must be married giving us the fact that M is also a male.

Therefore, M, N, P and R are males.